The clock is ticking for trucking manufacturers to meet challenging new emissions requirements in 2024 and 2027.
On those two horizons are reductions of NOx by up to 90 percent, CO2 by up to 25 to 30 percent plus new low load cycle and in-use specifications, as Eaton makes clear in a video on diesel cylinder deactivation (CDA). This emerging technology holds real promise in reducing emissions while improving fuel economy, but it’s the emissions battle that’s really taken center stage and driven the formation of various partnerships.
Eaton has worked with Cummins to test CDA in a Cummins Efficiency Series X15 engine. Cummins has also worked with Jacobs Vehicle Systems and Tula on cylinder deactivation. They all have the same goal of getting diesel engines up to the job of meeting new low-load requirements, like when the engine’s at idle or running at low RPMs. By shutting down half of the cylinders and decreasing air flow, CDA leads to increased exhaust temperatures in the remaining cylinders which in turn cranks up temperatures during the selective catalytic reduction (SCR) process. More heat equals fewer emissions.
Eaton, which has produced the CDA valve train assembly shown above, reports the ideal temperature in conventional diesel engines during SCR after treatment is between 250 and 400 degrees Celsius (482 and 752 degrees Fahrenheit). Engines can struggle to reach those temperatures during low-load cycles. Diesel CDA can raise SCR temperature 100 to 200 degrees Celsius (212 to 392 degrees Fahrenheit) during low-load conditions and ultimately exceed 500 degrees Celsius (932 degrees Fahrenheit) which drastically reduces NOx, CO2 and de-sulphates the SCR.
“The inclusion of a low-load cycle and being able to do better in that low power operation is really a challenge and that’s where cylinder deactivation is one of the key technologies that we’re evaluating for future regulations because it has the ability to not only increase those temperatures but improve fuel economy while you’re doing it,” said Lisa Farrell, Cummins’ director of advanced system integration.
“Most of our traditional methods today keep the catalyst warm and burn a lot more fuel. So with CO2 regulations and climate change goals, certainly that’s not the way we want to go for meeting future NOx regulations,” Farrell continued.
